Electric switch



Jan. 31, 1933. A, DODGE 1,895,918

ELECTRIC SWITCH Filed April 29, 1929 ITufe n v Patented Jan. 31, 1933 I PATE 1;- OFFICE.

ADIEL Y. DODGE, OF SOUTH BEND, INDIANA.

ELECTRIC SWITCH Application filed April 29, 1929. Serial No. 359,782.

This invention relates to electric switches and may be characterized as an improvement in electric switches of the type illustrated and described in the copending application of Harris C. Roth, Serial No. 358,792, filed April 29, 1929.

The present invention is not however, limited to use with the features of the above application, but may be employed 'as suitable or desired.

The primary object of the present invention is the provision of an improved envelope and liquid separator and, more particularly, the provision of a generally 1m,- proved and simplified envelope that may be formed more economically and expeditiously.

Another object is to reduce the operations and labor involved in the formation of these envelopes and to provide an envelope structure permitting the use of heavier glass than heretofore practicable.

Another object is to improve the evacuation of the containing tube or envelope.

Another object is to improve the mounting and actuating means for the switch.

Further objects and advantages of the present invention will appear from the following detailed description, taken in connection with the accompanying drawing, in which:

a Figure 1 is a side elevational view of a switch and actuating means, embodying the present invention and in closed circuit position;

tional view of the tubular stock of which the envelope is preferably formed.

Figure 2 is a View. similar to Figure 1, showing the switch tilted to open circuit position;

Figure 3 is a horizontal sectional View, taken on the line 3-3 of Figure 1;

Figure 4 is a transverse section, through one of the legs of the device, taken on the line 44 of Figure 3; I

Figure 5 is a fragmentary cross-section through the make and break connection be tween the legs of the device, taken on the line 5-5 of Figure 3;

' y the mercury or other conducting body 14 for Figure 1A 1s a fragmentary side elevaor other conducting body and for separating Figure 8 is a view similar to Figure 3,

of another form of the invention;

Figure 9 is a sectional view, taken on the line 99 of'Figure 8;

Figure 10 is a view similar to Figure 9, showing another shape for the make. and break connection between the legs of the device; and

Figure 11 is a diagrammatic View, showing the method of obtaining better evacuation.

In the embodiment of Figures 1 to 7, inelusive, 10 indicates the bulb or enclosing envelope, which is shown of generally U- shaped formation, w th the opposite legs 11 and the make and break connection 12 be tween these legs. The bulb or envelope 10 is preferably made of glass, although other suitable or preferred materials, having the' desired properties, are contemplated.

Where the bulb is of glass, the glass is preferably of a'character having high heat and are resisting properties, although this may vary. For example, with the thicker glass permitted by the present invention, a less expensive glass or other material might be suitable.

The tube or envelope 10 is adapted for holding and permitting movement or flow of thepurpose of opening and closing the electric. circuit. According to the present invention, the envelope 10 is preferably formed of a single length of straight glass tubing, indicated at 5 in Figure 1A, which tubing is heated and bent to the desired configuration. The form of the envelope may vary from the particular U-shaped configuration shown in Figures 1 to 10, but the particular configurations shown are illustrative of liquid switch envelope formations that may be formed 'of a single length of glass tubing and which are adapted for holding the mercury or dividing this body and permitting move me vantages *are' contemplated.

ment of the separated portions toward and away from each other in closing and opening the switch.

These are important aspects of the present invention and var-iationsin the form or contour of the envelope obtaining these ad- In the embodiment of Figures 1 to 7 the straight tube 5 of Figure 1A is heated and bent to generally U-shaped form. The opposite ends may be drawn and sealed, as at 1-5, to close the outer ends of the-legs 11 and it is to be understood that the tube or envelope.

may be evacuated as, for example, before sealing one ofthe ends at 15. --Where the make and break connection is reducedin section, as shown in Figurel, or decreased in width, as also shown in Figure 1, or where the make and break connection is humped at 30, as shown, inFigures 6 and 7 or other formations-diflerent from the normal condition of the tubing,}these' formations are inexpensively and expeditiously obtained by drawtions materially simplifies production and reduces the cost. At the same time, by forming the envelope in this manner, I find that the envelope may be made of thicker glass than practical where the bulb is blown with the separate wells blown directly out of the walls of the envelope or made up entirely separately and'fused to the main body of theenvelope, as heretofore.

The electrodes 16 and 17 may be sealed through the legs 11 with their inner ends dis posed to be connected by the mercury body 14 when the device is in the position shown in Figure land to be disconnected when the device is in the position shown in Figure 2.

It will be-understood that the electric circu tcontrolled by the switch is connected with the electrodes 16 and 17 and that this circuit is opened and closed by tilting the device from closed circuit position shown in Figure 1 to open circuit position shown in Figure 2, and

' vice versa. With the device shown in Figure 1, the amount of mercuryor other conducting 'fluid within the tube is suificicnt to fill the make and break connection 12 with the opposite ends of the body extending into-the legs 11 sufliciently to have good contact with the electrodes 16 and 17 and to form an electric connection between these electrodes through the body of mercury. When the device is tilted from the position shown in Figure 1 to-the position shown in Figure 2, the make and break connection 12 separates the body of mercury 14, as indicated at 20 in Figure 7 into two bodies 14 and 14, which, as the device is tilted to open circuit-position, move away fromeach other toward the closed ends of the legs 11 and, in tilting the device-to closed circuit position, move toward each other and meet at the point'of separation or make-and break point 20. This movement of the separated bodies 14' and 14 away from each other in -.the opening operation of the switch'and toward each other in the closing operation of the switch substantially doubles the speed ofmake andbreak. This tends to reduce arcing and toproduce a'clean make and break. I

Another feature of importance of this construction is that after the point of break is established the topmost portion of the bodies so I of conducting liquid separate and move away from one another in a direction at right angles to the plane of tilt.,, The tangent at the point of the curved bend where the break occurs is at right angles to-the plane of tilt and therefore has no inclination, regardless of thetilt. The efiective force of gravity is least at this point. that the mercury moves, the rate of tilt or the inclination increases both ways from this point. That is, as the tube is tilted from a horizontal. position the tangents at successive points around the curve from-the point of make and break make increasing angles withthe horizontal. break takes place, the mercury columns, and more particularly the mercury columns at the broken ends, encounter an increasing slope whereby the separating movement of the two bodies is accelerated. This acceleration is further increased due to the fact that when the break is established thecohesive force of the mercury is released, and substan- Traveling'in the path Therefore, after the bodies, due tothe tilted position of the device,

is operative to effect a quick separation thereof, whereas just before the mass of mercury separated the cohesive force of the mercury opposed the force of gravity. Thus in my construction the efiective force acting to separate the liquid is materially increased the instant the'break is completed and it continues to increase as the broken ends separate. As the broken ends move awa they continually encounter a steeper incline. It will be understood that the sharper the horizontal curvature of the connection 12 the greater will be the-proportion of increase.

The reduction ill-section of the connection 12 produces, in eflect, a relative enlargementin section of the legs 11, as shown, which augments the freedom of separating movement of the bodies 14" and 14", but this may .vary. With the tube formation of the mercury channel, additional separator bodies and the like may be omitted and the tube, in addition to forming .the separator, as well as the enclosure, encloses each mercury body 14 and 14", where the main body of mercury is separated, separately and prevents communication between these bodies, except through the make and break connection 12.

a The sectional contour of the connection 12 may be of any suitable or preferred shape.-

In the embodiment illustrated in Figures 1 to 7, the sectional width of this connection is reduced, as shown particularly in Figure 5. The relatively narrow or reduced width W (Figures 3 and 5) relative the depth or vertical dimension of the interior of the connection 12 reduces the width of the mercury body at the point of make and break and brake and this reduces or avoids undue heating and produces a better make and break than heretofore. This improvement in the making and breaking action of the switch and the reduction in heating eflect at the actual make and break point avoids or reduces injury to the enclosure 10 and enables carrying higher wattages than heretofore possible in switches of this type. Commonly, where the height of the channel or fluid holding and separating passages is no greater than the width .of said passage at thepoint of make and break, a rounded and even generally pointed meniscus is produced at the opposite ends of the separated fluid body. Two pointed or even two rounded ends will make and break with a point contact and the reduced body of mercury or other conducting fluid at this contact in the. make and break operation causes undue heating and arcing.

The present invention is not limited to a connecting portion of narrow width and I have, therefore, shown fragmentarily, in Figure 10, an embodiment in which this make and break connectlon 12 is of generally circular section. The section of Figure 10 is similar to I the section of Figure 5 and one of the legs of the tube is indicated fragmentarily at 11. As

' already explained, with the present invention,

the reduced section 12 of Figure 10, as well as the narrowed section 12,0f Figures 1 to 7 and the generally triangular section 12";of Figures8 and 9 are preferably obtained'by heating the tube and applying simple drawing or forming operations without blowing these connections or making them up separately and sealing to the remainderof the envelope.

For the purpose of action of the device,- the bottom surface 30 (Figure 6) ofthemake and break connection may be raised or humped slightly, as indicatfurther improving the ed. This raised portion 30, which may also be drawn or formed in the wall of the tube in the manner of the connection 12, is preferably disposed at the make and break .point '20 and; may be rounded as shown. In operation, the mercury or other conducting body makes and breaks over the raised surface or hump 30 and this raised surface tends to raise the actual section of separation and closing together ,of the ends 25 of the mercury body above the bottom surface 32 of the tube further than possible with the lower surface 32 in substantially the same plane and without the hump 30. lhis raising of the make and break point of the switch further above the surface 32 secures a further increase in the. efiective force of gravity in separating the two mercury bodies after the break has occurred, due

to the fact that just after the break the cohesive force of the mercury is released and the bodies separate by moving down the relatively steep sides of the hump. This construction further reduces the effect of heat and arcing upon this surface. 4

In the present case, as in the Roth application referred to, the make and break is preferably over a sweeping or majorradius, as' distinguished from a relatively sharp or localized corner.

In the embodiment of Figures '1 and 2, the

' tube 10 is shown mounted upon a support 35.

The tube 10 may be releasably attached to V the support 35 by means of spring clips 36, suitably secured to the support and embracing the tube to support the same upon the support 35 and against movement relative thereto. Pivoted at 40 and 41 to the opposite ends of the support 36 are a pair of link members 42 and 43, which link members cross one another at 44 and have fixed pivotal support at their J lower ends at 45 and 46, respectively. An actuating arm or link 48 is pivoted at 49 to the link 43 and this link 48 may be suitably connected with the thermostat or other actuating means for the switch.

To tilt the switch from closed circuit position, shown in Figure 1, to open circult position, the actuating force is applied in the direction of the arrow. in Figure 1. r This swings each of the link members 42 and 43 in a clockwise-direction about their respective pivots 45 and 46 and, with this swingingad. tion, the end of the support pivoted to the upper end of the link 43 is lowered and the opposite end of, this support is simultane-' ously raised by the pivotal connection with the upper end of the link-42. This crossed linkage 42, 43 reduces by one-half the amount a of movement necessary to obtain a certain Weighth inch inside-diameter at the make and legs 11' '0': the aa converge slightly toward their closed ends and the electrodes 16' and 17 are shown as entering the ends of 'these legs and extending internally of the legs to the desired points therein.

In this embodiment, the make and break a connection 12"is shown of generally triangular section with-the rounded-apex 52 at the bottom (-Figure 9). This triangular section of the make and break connection of the tube I is adapted fonnarrowing the width of this connection with the advantages set .out in connection with the embodiment/of Figures l-to 7-, and at the' same time, the triangular section is ad'a ted "for increasing the internal section of t is connection and for'providing a constant bottom radius at 52, which may be the same forall tubes over, say, three-sixteenths inch diameter. I find that a onebreak connection'ofthe-tube gives the most desirable meniscusand with this formation, this diameter or any suitable diameter may be provided at 52, regardlessof the crosssectlonal dimension *of the connection 12'.

' In Figure 11, the switchtube is indicated at 780 with a suitable heater indicated at 81 and a'duct or passage-82 leading from the top cien't heat to the tube to form mercury vapor therein, which is exhausted'through the conmercury need of one end of the tube to 'achamber 83; The

.mercury within the tube is indicated M84 and the heater is adapted for applying suiiiduit 82 to the chamber 83. It is to be understood that onl a slight percentage of the e va orized and the amount of 'mercury placed 1n the tube beforethis operation may be suflicient to compensate for this. This vaporization and exhaustion of mercury vapor provides'a better and more complete evacuation of the tubethan heretofore possible and the mercury may be recoveredfrom the chamber 83 as by collection in ,a' settling chamber anddistilling or in any I do not intend to be limited to the precisev details shown or-described.

Iclaim: v -1. In a liquid switch having a conducting liquidbody and adapted for opening and closing movement, a curved tube for holding and sealing thefliquid body, said tube having a circuit'making and breaking connection,

and a pair of liquid receiving and conducting legs angularly disposed relative thereto for receiving and permitting rescission of the liquid from said circuit making and breaking together to the wall of the tube.

connection'in. opening the switch and toward said connection in closing the switch, said circuit making and breaking connection hav-' ing a wall adapted for separating the liquid body into separate liquid bodies in the open-' ing movement of the switch, and each of said separate liquid bodies being movable in opposite directions'in' said legs'for novement away from each other in the openlng movement of the switch and toward each other in closing movement of the switch, the Walls of said clrcuit making and breaking connection 'at the point of break being brought closer form a reduced symmetrical section.

2. In a liquid flow switch having a conducting liquid body and adapted foropening and closing movement, a curved tube for holding andsealing the'l'iquid body, said tpbehaving a circuit making and breaking connection,

and a pair of liquid receiving and conductinglegs angularlydisposed relative thereto for receiving and permittingrescission' of the liquid in both legs-from said circuit making and breaking connection in opening the switch andtoward said connection in closing theswitch and said tube be-ingof elongated cross-sectionalong the circuit making and breaking connection for flattening the meniscus of the liquid along said connection, the

cross'section ofsaid legs being larger than said elongated cross section.

3. In a liquid flow switch having a conduct ing liquid body and adapted for opening and closing movement, a tube for holding and sealing the liquid body, said tube having a circuit making and breakingconne ction, and

a pair of liquid receiving and conducting legs angularly disposed relative thereto for 'receivlng and permitting, rescission of the liquid from said connection in opening the switch and toward said, connection in closing thelswitch, and the inner surface of said tube beingiiumped along said circuit making and breaking connection to increase the speed of separation of the liquid. 0 v

4. In a liquid flow switchhaving a conducting liquid body and adapted for opening and closing movement, a tube for holding and.

sealing the liquid body, said tube having a circuit makingand breaking connection, and a. pa r of liquid receiving and conducting legs angularly disposed relative-thereto for receiving and-permitting rescission of the liq- .uid from said circuit making and breaking connection in opening the switch and toward said connection in closing the switch and said tube being of; elongated cross-section along thecircuit making and breaking connection for flattening the meniscus of the liquid along said connection, and the inner surface of said tube being humped along said connection to space the region of make andbreak from 5. In combination, a liquid flow switch. a

support therefor, linkage comprisin a pair of cross links, each pivoted at one en to said support and having fixed pivotal support adjacent its opposite end, and actuating means having connection with said linkage.

6. In combination, a liquid flow switch, actuating means for tilting said switch, and a linkage connection between the switch and said actuating means and comprising crossed link means for lowering one end of the switch and link means for simultaneously raising the opposite end of the switch and vice versa.

7. A liquid flow switch having a conducting liquid body movable to open and closed circuit positions and comprisin the combination with said liquid body of tilting means for confining and separating the body of conducting liquid into two separate bodies each movable away from the other when the confining means is tilted, said means having a region which has no inclination regardless of the tilt and being formed with a raised portion centrally thereof so that as the broken ends of the llquid body separate the effective force of gravity acting to separate them is increased.

8. In combination, a liquid flow switch, a support therefor, linkage comprising a pair of links, each pivoted near one end to said support and at spaced apart points, said links having "fixed pivotal support ad acenttheir opposite ends and at, spaced apart points, the dlstance between one pair of pivots being diiferent from the distance between the other pair, and actuating means having connection with said linkage.

9. A liquid flow switch com rising a tubular holder for the liquid bo y affording a generally U-shaped passage .for holding and conducting the switch liquid, the cross section of said passage at the central portion being narrower relative to the other rtions of the passage and the invert of sai central portion havinga slope steeper than the other portions of the passage when the tubular holder is horizontalf v In witness whereof, I hereunto subscribe my name this 23rd day of April, 1929.

.ADIEL Y. DODGE. 

